Field
The described embodiments relate to techniques for establishing encrypted communication in a wireless mesh network. In particular, the described embodiments relate to techniques for defining a personal pre-shared key between pairs of electronic devices in a wireless mesh network.
Related Art
Many electronic devices are capable of wirelessly communicating with other electronic devices. For example, these electronic devices can include a networking subsystem that implements a network interface for: a cellular network (UMTS, LTE, etc.), a wireless local area network (e.g., a wireless network such as described in the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard or Bluetooth from the Bluetooth Special Interest Group of Kirkland, Wash.), and/or another type of wireless network.
One approach to wireless communication is to use a wireless mesh network (which is henceforth referred to as a ‘mesh network’). In a mesh network, multiple electronic devices (which are sometimes referred to as ‘nodes’) are organized in a mesh topology in which electronic devices communicate with each other via zero or more intermediate electronic devices or nodes. Typically, an electronic device in a mesh network communicates with its nearest neighbors. In a mesh network, a communication between two electronic devices via an intermediate electronic device or node is sometimes referred to as ‘one-hop’ communication, while the communication between the two electronic devices via two intermediate electronic devices or nodes is sometimes referred to as a ‘two-hop’ communication. Similarly, the communication between the two electronic devices via N intermediate electronic devices or nodes is sometimes referred to as an ‘N-hop’ communication.
The communication between two electronic devices in a mesh network (and, more generally, an arbitrary wireless network) can be secure. For example, a controller may distribute a pre-shared key (PSK) to the electronic devices in a mesh network. Subsequently, when two of the electronic devices in the mesh network securely associate with each other, the PSK may be used to authenticate the and to establish a secure connection between the two electronic devices.
However, it can be difficult to update the PSK in a mesh network. In particular, if an electronic device in the mesh network does not receive the updated PSK before the mesh network switches over to using the updated PSK (e.g., because of: a power failure, wireless interference, a hardware failure, rebooting of the electronic device, a hacker attack, etc.), then this electronic device may not be able to subsequently communicate with the other electronic devices in the mesh network.